function changeValueLoginHiddenField(){

  var btnLogin = 'Login';
  document.getElementById("txtValueBtn").value = btnLogin; 
}

function changeValueRegisterHiddenField(){
	  var btnRegister = 'Register';
	  document.getElementById("txtValueBtn").value = btnRegister; 

}

function changeValueLogoutHiddenField(){
	  var btnRegister = 'Logout';
	  document.getElementById("txtValueBtn").value = btnRegister; 

}

function changeValueQuantityField(){

}